This typical 2nd winter was
photographed by Dusan
Brinkhuizen near Almere in the
Netherlands on 6 november 2004. The grey mantle, (mostly)
immature coverts and tertials and overall dark tail make this
bird a 2nd winter. Note that this bird shows a white mirror at
the underside of P10 (pictures below). This is a very common
feature in cachinnans (and Greater Black-backed Gull)
and very uncommon in argenteus Herring and Yellow-legged
Gull.